In a school, the ratio of adults to the number of children is 4 : 9.
The ratio of the number of boys to the number of girls is 5 : 2.
There are 27 more boys than girls.
How many people are there in the school?
Adults |
Children |
4 x 7 |
9 x 7 |
|
Boys |
Girls |
|
5 x 9 |
2 x 9 |
28 u |
45 u |
18 u |
The number of children is the combined repeated identity.
Make the number of children the same using the LCM of 9 and 7.
LCM of 9 and 7 = 63
Number of more boys than girls
= 45 u - 18 u
= 27 u
27 u = 27
1 u = 27 ÷ 27 = 1
Number of people
= 28 u + 45 u + 18 u
= 91 u
= 91 x 1
= 91
Answer(s): 91